Dispensing systems which dispense one or more chemical products diluted with a diluent such as water are generally known in the art. Chemical products may be provided in solid block form, powder form, liquid concentrate, gel, or other compositions known in the art. Conventional dispensing systems dilute the chemical products with water to form a solution having a controlled concentration of chemical product therein. Other dispensing systems may be non-homogeneous, whereby chemical products are dispersed or suspended in a liquid.
Dispensing systems which are portable have become increasingly popular, particularly in the cleaning area, to enable maintenance personnel for a facility to generate cleaning solutions close to a point of use. Portable dispensing systems typically require a source or supply of diluent, e.g., a standard water faucet on a utility sink. Portable dispensing systems typically dispense into a mop bucket, sink, or they may alternatively dispense into separate containers within the dispensing system, e.g., for filling individual spray bottles with cleaning solution.
However, many portable dispensing systems do not directly comply with various plumbing codes established throughout the U.S. and abroad. For example, many plumbing codes require some sort of backflow prevention device, such as an air gap or check valve, to prevent the contamination or pollution of a water supply due to contaminants backing up into the water supply. Another potential concern is due to possible cross contamination of hot and cold water supplies, where water from one supply may flow into the other if the supplies are connected and one of the supplies is at a greater pressure than the other. Also, faucets are often installed above a sink or basin to provide an air gap and thereby prevent the faucet from ever being submerged.
To comply with plumbing codes, many facilities include atmospheric vacuum breakers and the like for providing backflow prevention. Many of these devices, e.g., atmospheric vacuum breakers, are not designed to be left under line pressure. Many portable dispensing systems, however, present a problem when attached to conventional water supplies because they may cause the existing backflow prevention devices installed with the water supply to be subjected to continuous line pressure.
For example, many chemical product dispensers are attached to a faucet through a hose and optionally a quick connect fitting, and have a downstream control valve for controlling the dispenser by regulating the flow of water into the dispenser. Consequently, when a dispensing system is attached to a faucet and the faucet is turned on, but the dispenser is not actuated, the line pressure which builds up in the inlet line of the dispenser may cause damage to the atmospheric vacuum breaker.
Accordingly, many manufacturers of dispensing systems recommend that the master control for a dispenser be the control valve (typically the faucet) of the water supply, and further that the dispensing system be disconnected from the water supply when not in use. Many maintenance personnel, on the other hand, often disregard these instructions and leave the dispensing system attached to a water supply with the water supply faucet open, instead using the dispenser control valve to dispense chemical product solution when needed.
To anticipate this potential use by maintenance personnel, many plumbing codes require a facility to hard plumb a separate backflow prevention device (which is designed to be subjected to continuous line pressure) onto each existing faucet installation where a portable dispenser will be used. Each installation requires a building permit and is relatively costly to install, maintain, and inspect on a yearly basis. This problem is magnified when a facility wishes to use dispensers at multiple faucets throughout the facility.
Therefore, a need exists for a dispensing system which may be connected to existing plumbing without substantial modification to the existing system, without damaging any backflow prevention devices attached thereto, and without conflicting with any established plumbing codes.